Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.15 (pectinase)
 2,440 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Commercial citrus pectin containing galacturonic acid and rhamnose in a ratio of approximately 40:1 was saponified and then exhaustively digested with endopolygalacturonase (EPG). The products were separated by ultrafiltration into low-molecular-weight (LMW) and high-molecular-weight (HMW) fractions. The LMW fraction accounted for 80% of the starting material, but for only 10% of the total rhamnose. The molar ratio of galacturonic acid to rhamnose of the LMW fraction was 236, suggesting that very few small Rha-containing oligomers were generated by the EPG digestion. No distinct Rha-containing oligomers were found by various chromatographic analyses of the LMW fraction. The HMW fraction, which only accounted for 10% by weight of the starting pectin, contained more than 85% of the rhamnose. The ratio of GalA to Rha in the HMW fraction was 1.7:1 and partial acid hydrolysis of this fraction produced a series of oligomers consisting of GalA-Rha repeating units, suggesting that it contained rhamnogalacturonan, which has a backbone composed of GalA-Rha disaccharide repeating units. The HMW fraction also contained large amounts of arabinose and galactose, which probably originated from side chains linked to some of the rhamnose residues. We propose that commercial citrus pectin is composed of two regions: the predominant region consists of chains of uninterrupted 1,4-linked alpha-D-GalA residues with between 60-70% of the residues methyl esterified; and the other region consists of rhamnogalacturonan with a backbone composed of GalA-Rha disaccharide repeating units and neutral sugar side chains.
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PMID:Scarcity or complete lack of single rhamnose residues interspersed within the homogalacturonan regions of citrus pectin. 971 29

The exo-1 mutant of Neurospora crassa produced and secreted pectolytic activities when incubated in the presence of pectin-containing biological materials. This study shows that polygalacturonase, pectate lyase and pectin lyase activities were induced in media supplemented with galactose or galacturonic acid, indicating that these sugars induced the synthesis of pectinases. Pectinesterase activity was undetectable. Polygalacturonase activity was better induced by galactose than by galacturonic acid. The reverse was true for lyase activities. The inducing effect of galactose and galacturonic acid seemed to be different: (i) a mixture of galactose and galacturonic acid synergistically increased the production of pectic enzymes, as compared to that in the presence of one of these sugars; (ii) the inducing effect of galacturonic acid was partially repressed by glucose; (iii) in contrast, the inducing effect of galactose, rather than repressed, was enhanced by the presence of glucose. Altogether, these data point out to a complex mechanism of regulation of pectolytic enzymes by pectin-containing organic substances.
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PMID:Regulation of pectic enzymes from the exo-1 mutant strain of Neurospora crassa: effects of glucose, galactose, and galacturonic acid. 972 23

Germlings of Botrytis cinerea, an important fungal pathogen of plants, produce an extracellular matrix (ECM), or ensheathing film, that serves, in part, in their attachment (R. P. Doss, et al., Appl. Environ. Microbiol. 61:260-265, 1995). The composition of this film has been ascertained by using samples obtained by growing germlings on a glass surface, removing the fungal mycelium by vigorous washing, and collecting the tightly attached film by scraping the substratum with a razor blade. Slightly over half of the dry weight of the ECM was found to be carbohydrates (about 20%), proteins (about 28%), and lipids (about 6%). Hydrolysis of the carbohydrate portion of the ECM revealed that glucose was the most prominent monosaccharide present, comprising about 60% of the total monosaccharides. Also present were mannose (about 35%) and myo-inositol (about 5%). The proteinaceous fraction of the ECM was made up of a number of polypeptides separable by polyacrylamide gel electrophoresis. The lipid fraction of the ECM, analyzed by thin-layer chromatography, was made up of several simple lipid components, including free fatty acid, mono- and triacylglycerol, wax ester, fatty alcohol, and several unidentified components. No complex lipids were detected. Isolated ECM exhibited polygalacturonase and laccase activity and was able to catalyze the hydrolysis of p-nitrophenyl butyrate, a model substrate for assessing cutinase activity. Cellulase, pectin lyase, and pectin methyl esterase activities were noted with both heated and unheated ECM preparations. Proteinase activity was not detected.
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PMID:Composition and enzymatic activity of the extracellular matrix secreted by germlings of botrytis cinerea. 992 60

The carbohydrate chains of recombinant endopolygalacturonase I (EPG I) from Aspergillus niger were characterized using a combination of mass spectrometric techniques. High performance liquid chromatography (HPLC) in conjunction with electrospray ionization mass spectrometry was used to separate the components of EPG I liberated by trypsin digestion. In-source collision-induced dissociation (CID) was utilized to fragment the digestion products entering the mass spectrometer, and the generation of carbohydrate fragment ions allowed for the identification of glycopeptides. The masses of the resulting glycans were calculated and entered into a carbohydrate database to search for possible structures. The primary sequences of the carbohydrate chains were confirmed by digesting aliquots of the intact glycopeptide with endo- and exoglycosidases and then analyzing the digestion products using matrix-assisted laser desorption/ionization mass spectrometry. These experiments demonstrated that one of the two N-linked sites of EPG I was occupied by a series of high-mannose structures, the second N-linked site was not occupied, and no O-linked sites were detected.
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PMID:Characterization of the glycosylation of recombinant endopolygalacturonase I from Aspergillus niger. 1040 37

The production of cell wall-degrading enzymes (wall depolymerases) by plant pathogenic fungi is under catabolite (glucose) repression. In Saccharomyces cerevisiae, the SNF1 gene is required for expression of catabolite-repressed genes when glucose is limiting. An ortholog of SNF1, ccSNF1, was isolated from the maize pathogen Cochliobolus carbonum, and ccsnf1 mutants of HC toxin-producing (Tox2(+)) and HC toxin-nonproducing (Tox2(-)) strains were created by targeted gene replacement. Growth in vitro of the ccsnf1 mutants was reduced by 50 to 95% on complex carbon sources such as xylan, pectin, or purified maize cell walls. Growth on simple sugars was affected, depending on the sugar. Whereas growth on glucose, fructose, or sucrose was normal, growth on galactose, galacturonic acid, maltose, or xylose was somewhat reduced, and growth on arabinose was strongly reduced. Production of HC toxin was normal in the Tox2(+) ccsnf1 mutant, as were conidiation, conidial morphology, conidial germination, and in vitro appressorium formation. Activities of secreted beta-1,3-glucanase, pectinase, and xylanase in culture filtrates of the Tox2(+) ccsnf1 mutant were reduced by 53, 24, and 65%, respectively. mRNA expression was downregulated under conditions that induced the following genes encoding secreted wall-degrading enzymes: XYL1, XYL2, XYL3, XYL4, XYP1, ARF1, MLG1, EXG1, PGN1, and PGX1. The Tox2(+) ccsnf1 mutant was much less virulent on susceptible maize, forming fewer spreading lesions; however, the morphology of the lesions was unchanged. The Tox2(-) ccsnf1 mutant also formed fewer nonspreading lesions, which also retained their normal morphology. The results indicate that ccSNF1 is required for biochemical processes important in pathogenesis by C. carbonum and suggest that penetration is the single most important step at which ccSNF1 is required. The specific biochemical processes controlled by ccSNF1 probably include, but are not necessarily restricted to, the ability to degrade polymers of the plant cell wall and to take up and metabolize the sugars produced.
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PMID:The Cochliobolus carbonum SNF1 gene is required for cell wall-degrading enzyme expression and virulence on maize. 1066 60

Stereum purpureum endopolygalacturonase (endoPG; EC 3.2.1.15) is a causal protein for silver-leaf disease in apple trees. Endopolygalacturonase I, is a mixture of three components (Ia, Ib, and Ic) that produce three bands on SDS/PAGE but have the same polypeptide and sugar chains. Electrospray ionization mass spectrometry (ESI-MS) analysis of three endoPG I proteins and deglycosylated endoPG Ia revealed a molecular mass of 37 068, 38 285, and 39 503 for Ia, Ib, and Ic, respectively; the number of N-binding sugar chains matches that of a high-mannose type of sugar chain. Two, three, and four sugar chains are present in endoPG Ia, Ib, and Ic, respectively. Deletion of 44 amino acids from the deduced sequence occurred in the C-terminal region. Positions of the glycosylation sites and disulfide bridges were decided by tryptic digestion followed by liquid chromatography-electrospray mass spectrometry (LC-ESI-MS) analysis of reductive and nonreductive pyridylethylated endoPG I proteins. The glycosylated asparagines were determined to be Asn92 and 161; Asn92, 161, 279, or 302; and Asn92, 161, 279, and 302 in Ia, Ib, and Ic, respectively. Three disulfide bridges were noted at Cys3-Cys17, Cys175-Cys191, and Cys300-Cys303. These results are the first findings for fungal endoPG and may contribute to clarification of the relationship between stereostructure and catalytic activity.
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PMID:Determination of glycosylation sites, disulfide bridges, and the C-terminus of Stereum purpureum mature endopolygalacturonase I by electrospray ionization mass spectrometry. 1075 64

Water-soluble polysaccharide fractions VO1-VO4 were isolated from the squeezed berries of snowball tree (Viburnum opulus) by successive extraction with water at various temperatures and pH and with aqueous solutions of ammonium oxalate. These fractions were purified by ion-exchange chromatography on DEAE cellulose, and the homogeneity of the purified polysaccharides was determined by gel filtration on Sephacryl S-500. Acidic polysaccharides close to pectins in their sugar composition were found in all the extracts (fractions VO1-1, VO2-1, VO3-2, and VO4-2). Residues of galacturonic acid, galactose, arabinose, and (to a lesser extent) rhamnose are their main constituents. Neutral polysaccharides composed mainly of galactose and mannose residues were additionally found in fractions extracted with acidified water (pH 4.0) and with aqueous ammonium oxalate solutions. Partial acidic hydrolysis and digestion with pectinase of acidic polysaccharides indicated that their carbohydrate backbone consists of alpha-1,4-linked residues of D-galacturonic acid. NMR spectra of acidic polysaccharides (fractions VO3-2 and VO3-3) confirmed this and demonstrated that their side oligosaccharide chains are composed of beta-1,4-linked galactopyranose residues and of terminal and 2,5- and 3,5-substituted residues of alpha-arabinofuranose at a Gal: Ara ratio of 3:1. Some polysaccharides from V. opulus were found to possess an immunostimulating activity: they enhance phagocytosis, in particular, the phagocytic index and the secretion of lysosomal enzymes with peritoneal macrophages. Calcium ions were found to be necessary for the appearance of the stimulating effect of acidic polysaccharides from V. opulus.
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PMID:[The isolation, preliminary study of structure and physiological activity of water-soluble polysaccharides from squeezed berries of Snowball tree Viburnum opulus]. 1080 53

Polysaccharides from the roots of Panax ginseng were extracted by hot water and fractionated by using ethanol precipitation and ion exchange chromatography. Fractions FC (crude extract), F1 (fraction precipitated by ethanol), F1N (fraction unbound to DEAE-Sepharose CL-6B), and F1A (bound fraction) were obtained. Their carbohydrate analyses showed that acidic fraction F1A contains higher amounts of galactose, arabinose and uronic acids, in comparison to FC and F1. Fraction F1N mainly consists of glucose. The inhibition of Helicobacter pylori-induced hemagglutination revealed different inhibitory activities of these fractions. In particular, acidic fraction F1A showed a remarkable inhibitory activity (minimum inhibition concentration was 0.25 mg/ml) among the polysacharide fractions. However, digestion of the fraction F1A with pectinase resulted in a lower molecular weight oligosaccharide fraction F1AP which was non-inhibitory at the concentration of 4 mg/ml. Comparison of inhibitory activities and carbohydrate compositions of isolated fractions indicates that the activity correlated with the contents of galactose, arabinose, and uronic acids. These data suggest that acidic polysaccharides may be responsible for the inhibitory activity.
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PMID:Inhibition of Helicobacter pylori hemagglutination by polysaccharide fractions from roots of Panax ginseng. 1082 Oct 45

Silenan SV, a pectic polysaccharide, was isolated from the aerial part of Silene vulgaris (Moench) Garke (Oberna behen (L.) Ikonn.), widespread through the European North of Russia. The polysaccharide was found to contain residues of galacturonic acid (63%), arabinose, galactose, and rhamnose as the main constituents. The results of a partial acidic hydrolysis, pectinase digestion, and NMR studies of silenan SV indicated that its molecule contains a linear alpha-1,4-D-galacturonan backbone and ramified regions. The core of the ramified regions is composed of residues of alpha-1,4-D-galacturonic acid along with 2-substituted alpha-rhamnopyranose residues. The NMR data showed that the silenan SV side chains are composed of the blocks built from the terminal alpha-1,5-linked arabinofuranose and beta-1,4-linked galactopyranose residues; these most likely are the side chains of rhamnogalacturonan, characteristic of other pectic polysaccharides. The nonreducing ends of these side chains contain alpha-arabinofuranose residues.
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PMID:[Isolation and structural study of polysaccharides from campion Silene vulgaris]. 1103 28

A pectic polysaccharide, lemnan, was isolated from freshly collected duckweed Lemna minor L. Its sugar chain was shown to be mainly composed of the residues of D-galacturonic acid (64%), galactose, arabinose, xylose, and D-apiose, a branched chain sugar. The high content of D-apiose (25%) indicated that lemnan is an apiogalacturonan type pectin similar to zosteran, a pectic polysaccharide from a sea phanerogam of the Zosteraceae family. The results of partial acidic hydrolysis, pectinase digestion, and NMR studies of lemnan demonstrated that its macromolecule contains regions of the linear alpha-1,4-D-galacturonan and branched apiogalacturonan. The side chains of apiogalacturonan were found to be formed of single and 1,5-linked residues of D-apiofuranose attached to 2- and 3-positions of the D-galacturonic acid residues of the apiogalacturonan backbone. Lemnan was shown to exhibit an immunomodulatory effect by activating the system of phagocytosis.
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PMID:[Structure and physiological activity of lemnan, Lemna minor L. pectin]. 1122 Dec 55


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